Derivation of a Sun-tracking law for payloads with pointing restrictions in the UPMSat-3 mission

Abstract

Satellites dedicated to remote sensing either for the Earth or space, typically require their instruments to be pointing toward the location of their object of study. These satellites can face significant challenges as different components also have its own pointing requirements to be operative or work optimally. For instance, we have the case of solar panels for electrical power generation, where perfect pointing of the panels toward the Sun can affect negatively to payload operation. Common solutions for maximizing power generation include the usage of orientable solar panels. However, this approach increases the complexity of the satellite, raising the cost of the solar panels and their associated mechanism. In this study, we propose a new approach that enables high-consuming remote sensing payloads to operate for extended periods without using orientable solar panels. To ensure maximum power generation without compromising the satellite’s pointing constraints, an optimal tracking law is derived. This law maximizes the projected solar array area at each instant, resulting in maximum electrical power generation. The proposed method is validated against an actual mission scenario. This work offers significant benefits for satellite operators, reducing the need for costly orientable solar panels and enhancing the overall efficiency of satellite missions.